I know it's a little late for posting, but here I go anyway:
You might wonna check out Luxor - a free GPL'ed open-source project -
that tries to bring XUL and Python to the masses without using the
Mozilla Gecko machinery. In a way it's a free-standing, clean-room
implementation of XUL built using Java. It currently is available in a
Swing UI toolkit flavor and an Eclipse UI toolkit flavor (aka Standard
Widget Toolkit/SWT) is in the works.
Find out more @ http://luxor-xul.sourceforge.net
To get started using XUL and Python grab the luxor-python-examples
package in the download section.
- Gerald